The present invention, in some embodiments thereof, relates to a stylus-enabled digitizer system and, more particularly, but not exclusively, to a system and method for tracking orientation of a stylus with respect to a digitizer.
Digitizer systems are used as computer input devices for capturing data or handwritten signatures, text, drawings, symbols or the like. Digitizing tablets and/or touch screens are exemplary digitizer systems used to replace a mouse as a primary pointing and navigation device for desktop computers. A user interacts with the digitizer system by positioning and moving an object such as stylus and/or a finger over a sensing surface of the system, e.g. a tablet and/or a touch screen. Location of the object with respect to the sensing surface is tracked by the digitizer system and interpreted as a user command. An electromagnetic stylus is one type of stylus known in the art for operating a digitizer system. The electromagnetic stylus operates by emitting an electromagnetic signal at or near the writing tip that can be picked up at locations on the sensing surface of the system. Position detection can typically be performed while the object is either touching and/or hovering over the sensing surface.
U.S. Pat. No. 6,690,156 entitled “Physical Object Location Apparatus and Method and a Platform using the same,” U.S. Pat. No. 7,292,229 entitled “Transparent Digitizer,” and U.S. Pat. No. 7,372,455 entitled “Touch Detection for a Digitizer,” all of which are assigned to N-trig Ltd., the contents of all of which are incorporated herein by reference, describe a device for detecting objects disposed in association with a graphical display device. The device includes a transparent sensing arrangement of detectors located on the display screen that provide output to detect a location of the object in relation to the display screen.
In U.S. Pat. No. 7,292,229 there is also described an electromagnetic stylus designed to generate an electric field concentration in the vicinity of the front tip so that a location of the stylus with respect to the display screen can be accurately determined. It is described that the stylus can optionally also generate an electric field concentration in the vicinity of a reverse tip located at a second end remote from the front tip for detecting location during an eraser event. Variations in the electric field generated at each of the tips can be introduced to differentiate between an eraser event and a front tip event.
US Patent Application Publication No. 20130088465 entitled “Object Orientation Detection with a Digitizer,” assigned to N-trig Ltd., the contents of which are incorporated herein by reference, describes a stylus including a plurality of spaced apart transmitters, a digitizer sensor that detects transmission from each of the transmitters at a projected location on the digitizer sensor and circuitry associated with the digitizer sensor for determining an orientation of the object based on a geometric relationship between the projected locations.